This renewal application is a request for continuing support of an eight-bed General Clinical Research Center at the Medical University of South Carolina. Major areas of investigation include biochemical characterization of bone and mineral metabolism in blacks; influence of tight metabolic control on lipoprotein-platelet interaction and long-term complications of diabetes mellitus; interrelationships among the immune system, Vitamin D and tuberculosis ; characterization of thromboxane A2 receptors in platelets of patients undergoing percutaneous coronary artery angioplasty; pathogenesis of the Williams syndrome; albumin metabolism in patients on chronic peritoneal dialysis; treatment of scleroderma by photopheresis and of scleroderma renal disease with inhibitors of angiotensin-converting enzyme; pathogenesis of scleroderma lung disease; characterization of tryptophan metabolism in scleroderma and of leucovorin metabolism in normal subjects and patients undergoing treatment with methotrexate; treatment of panic disorders in chronic alcoholics; renal kallikrein-kinin system in sodium chloride homeostasis and blood pressure regulation in blacks; renal kallikrein-kinin system in hyperfiltration of diabetes mellitus and response to dietary protein; and influence of sex steroid hormones on drug clearance. The proposed investigations are to be carried out in an environment that emphasizes interdisciplinary collaborations between basic scientists and clinical investigators. Application of analytical and synthetic chemistry and biochemistry to clinical research is an important activity of the studies that are being conducted on this General Clinical Research Center.